O’Melveny Worldwide

Patrick Plassio’s diverse practice includes complex commercial disputes of all sorts, with a focus on technology-related matters. He has litigated cases involving patents, copyrights, trade secrets, fraud, and breach of contract. Patrick has experience in all pre-trial phases of a case—he has conducted internal and pre-trial investigations; led teams through complex e-discovery issues and subpoena responses; taken, prepared witnesses for, and defended depositions; and briefed and argued dispositive motions and appeals. A skillful negotiator, Patrick routinely advocates for clients in discussions with opposing parties to resolve procedural and discovery disputes, along with cases in their entirety. He serves clients in the telecommunications, media, technology, manufacturing, and energy industries, among others.

After graduating from law school, Patrick clerked for the Honorable Xavier Rodriguez of the United States District Court for the Western District of Texas, where he was immersed in federal practice and procedure, as well as in cases centered on intellectual property, voting rights, the Endangered Species Act, and wage and hour law.

Technology, IP, and Trade Secrets

  • Defended developer of solar power facilities against claims for misappropriation of trade secrets and breach of contract, including by leading a complex document collection and production effort and successfully negotiating a favorable resolution
  • Defended telecommunications company against patent infringement lawsuits related to internet filtering technology
  • Represented manufacturer of telecommunications hardware in action for breach of contract and against fraud and trade secret counterclaims related to energy-efficient financing
  • Represented manufacturer of semiconductors in intellectual property dispute involving complex claims for breach of a technology license agreement and patent infringement
  • Defended international software developer against claims of patent and copyright infringement
  • Represented media company in pursuing claims against provider of streaming services for indemnification against patent infringement claims, including by successfully briefing and arguing numerous dispositive and discovery motions
  • Represented clients in the food and beverage, media, transportation, and energy industries in trade secret matters related to the enforcement of non-competition agreements, including litigating requests for emergency injunctive relief
  • Represented consumer electronics company in pursuing claims against former employee involving for misappropriating trade secrets and leaking them to the press, including by successfully negotiating a favorable resolution

Merger and Acquisition Litigation

  • Represented technology company in earn-out litigation against a former executive
  • Represented purchaser of a manufacturing company in pursuing claims against seller for fraud in concealing anticipated declines in revenue
  • Represented energy company in enforcing indemnification rights in an agreement through which it had acquired a subsidiary

Class Actions

  • Defended manufacturer of plumbing parts in multi-national, multi-district products liability class action
  • Defended multiple financial services companies against claims in putative class actions alleging various fiduciary breaches and prohibited transactions under ERISA

Other Litigation Matters

  • Defended oilfield services company against claims for tortious interference, business disparagement, unfair competition, and violations of the Lanham Act, securing complete and voluntary dismissal of plaintiff’s claims after filing of a motion to dismiss
  • Represented investment funds before the Texas Supreme Court in an appeal of the denial of their motion under the Texas Anti-SLAPP statute
  • Asserted breach of contract claims for manufacturing company in cross-border case involving receipt of polluted goods, including by successfully arguing a dispositive motion and an interlocutory appeal of the same

Pro Bono

  • Prosecuted claims on behalf of a plaintiff in a motor vehicle collision lawsuit
  • Represented group of domestic violence survivors in an amicus brief filed in the United States Supreme Court in a case involving standards applicable to international child custody cases under the Hague Convention; on a subsequent appeal to the Second Circuit following remand in the same case, represented a group of academics, medical professionals, and child welfare advocates in an amicus brief in urging consideration of the child’s special circumstances

Additional Experience

  • Advised leading digital asset trading platforms on potential legal and regulatory issues arising from potential cryptocurrency listings
  • Conducted internal investigation of technology company related to employment law issues and best practices
  • Conducted internal investigation of technology company related to potential shareholder suit
  • Advised clients on best practices, policies, and procedures for maintaining privilege in internal communications


Bar Admission

  • Texas

Court Admissions

  • US District Court for the Northern, Eastern, and Southern Districts of Texas


  • University of Texas School of Law, J.D., with high honors; Associate Editor, Texas Law Review; Chancellors; Order of the Coif; Dean’s Achievement Award for Highest Performance in Admiralty Law
  • St. John’s University, B.S., Journalism & Sport Management: summa cum laude; Gold Certificate of Achievement in Journalism

Professional Activities


  • Honorable Xavier Rodriguez, US District Court for the Western District of Texas